NOx Sensor Heater Control Circuit/Open Bank 1 Sensor 1
What it means
P2205 means the PCM detected an open in the heater control circuit of the bank 1, sensor 1 NOx sensor. That heater brings the sensor up to operating temperature so it can measure nitrogen-oxide levels for the emissions system. When the heater circuit is open the sensor can't work, but the engine itself still runs normally — so this is primarily an emissions fault. The usual causes are a failed NOx sensor, broken heater wiring, a bad connector, or a lost power supply.
Can I keep driving? Drivable — this is an emissions fault, but on some diesels repeated NOx faults can trigger a speed-limiting derate, so don't leave it unrepaired.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- Failed emissions test
- Possible DEF/SCR or reduced-power warning on diesel applications
Common causes
Most likely first
- Faulty NOx sensor (the heater is built into the sensor)Likely
- Open or shorted NOx sensor heater control wiringCommon
- Poor or corroded connector at the NOx sensorCommon
- Blown fuse or lost power supply to the sensorLess often
- Faulty NOx sensor module or PCM driver (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for companion NOx sensor codes.
- Inspect the bank 1 sensor 1 NOx sensor connector and wiring for opens, shorts, and corrosion.
- Confirm the sensor has power and ground, and check the feeding fuse.
- Measure the heater circuit for continuity; an 'open' fault means a break somewhere in that circuit.
- Replace the NOx sensor if the heater is open internally. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2205?+
Can I just clear P2205?+
Related codes
Often seen with P2205
Read & clear P2205 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.